Nobody knows why the babies are dying near Weldon Spring. But the grownups can't help asking whether the site's toxic stew is to blame.

By now, Kleba's office was piled high with files and documents people had pressed upon him. He had no intention of grappling with the science himself; he was trusting the experts, pushing them to do what he believed they should. He'd heard enough to grasp that the stats were on the site's side: There were no obvious exposure pathways; heavy metals rarely wandered far from home; test results had dropped to "safe" levels. But what was a "pathway," and what was "safe"? Dust blows. Water seeps through limestone. Gases fly. Could enough have escaped to do any harm?

By the "maximum contaminant load" standards of the EPA, what has escaped -- at least the part that's been measured -- is within safe limits. But MCLs aren't based on health. They're compromises that consider the cost of remediation and the availability of technology. It's the MCL goal that's "protective of adverse human health effects and allows an adequate margin of safety." And the goal, for TCE and radionuclides and many of the other Weldon Spring contaminants, is zero.

Jennifer Silverberg

"It's easier for me to believe in God than in the government," says Father Gerry Kleba.

In the real world of environmental remediation, though, zero's risible. The baseline is usually ALARA: "as low as reasonably achievable." So how much of this reasonable exposure is needed to cause, say, cancer or birth defects? "That's easy," says Ozonoff. "Nobody knows. Generally we believe there is some risk at every level of exposure. Cancer starts with a single cell going bad. So all you have to do is, excuse the expression, fuck up that first cell, and it doesn't take much chemical to do that.

"Here's what the EPA will tell you -- incorrectly, by the way," he continues. "They will say, 'We test these things at high doses in animals and then we extrapolate down to the low dose and we make the estimate conservative.' OK. Draw a graph. In the upper right corner, put two dots, for high dose and high risk. In the lower left, draw dots for low dose and low risk. That's where you want to get to, so draw a line." He waits two seconds. "How'd you draw that line? You could've drawn it an infinite number of ways. The EPA has a particular mathematical formula for it, but what they don't tell you is, there are probably half-a-dozen plausible formulas, and if you chose one of the others, the risk could be up to 10,000 times higher. For TCE, it is 10,000 times higher."

What about the dangers of low-level radiation? "Again," says Ozonoff, "they're hard to measure. What we know about radiation's effects on humans, we know only after the fact, from crises and not controlled experiments. And nature's a lousy research assistant." Some scientists now believe low-level radiation is even more dangerous than high levels, because instead of killing cells outright, it merely damages them, throwing cell reproduction askew.

Even the cautious National Academy of Science is re-evaluating "Health Effects from Exposure to Low Levels of Ionizing Radiation" -- and just requested a deadline extension to 2003. More fervent scientists at the independent Radiation and Public Health Project are convinced that radioactive fallout and residues are beginning to mix with industrial pollutants, multiplying each other's carcinogenicity and other toxic effects.

"Interaction's the frontier we're on right now, and we don't know much about it," admits Ozonoff. We do know that some particulates soak up toxic vapors and help them travel farther. Some substances enhance the absorption of others or intensify them. Volatile organics such as TCE combine with nitrogen oxides to create poisonous ground-level ozone. In Toms River, N.J., epidemiologists studied a Superfund site and found that "things had gotten mixed together," finishes Ozonoff, "creating a styrene so unusual there's nothing in the literature about it."

And the witches' brew at Weldon Spring? "It is very unlikely that there are any adverse effects due to the contaminants interacting with one another, especially given the extremely low concentrations," says Bruce Ballew of the DOE.

Meanwhile, the new St. Charles County Community Health Assessment Survey asks whether people wear seatbelts, take vitamins and wash their hands after using the restroom, but it doesn't ask a single question about miscarriages, birth defects or environmental contaminants. The Missouri Department of Health Web site lists the risk factors for cancer as nutrition, obesity, physical inactivity and smoking but doesn't mention a word about toxic exposures.

According to a General Accounting Office report submitted to Congress last May, toxic exposures are of paramount public concern. The GAO urged states and federal agencies to test exposures directly, through blood, urine and tissue samples, instead of randomly plucking bits of air, water and soil and generalizing about how people -- who are actually very different from each other -- absorb various substances. Scores of federally funded studies are examining the effects of toxic chemicals at Superfund sites on surrounding communities.

Missouri's Department of Health places the blame elsewhere.

"Most communities we have to work with, they already have their mind set that there is something [environmental] in that community," says Simoes. "It's a natural tendency in human beings: We try to find some cause that is not us. But it's behavior that causes most cancer."